Application of reverse phase ion-pair partition chromatography to drugs of forensic interest

A method is described for determining a wide range of abused drugs by using 1 column, a single isocratic system, and a fixed wavelength (254 nm) ultraviolet detector. Paired-ion chromatography is performed on a reverse phase muBondapak C18 column. Acidic, basic, and neutral drugs, including their corresponding salts, can be determined without prior cleanup. A counter ion, 1-heptane sulfonate, is dissolved in the aqueous organic mobile phase to give a final pH of approximately 3.5. This technique is applicable to ergot alkaloids, phenylethylamines, opium alkaloids, local anesthetics, barbiturates, and other drugs of forensic interest. Five major opium alkaloids in gum opium, namely, morphine, codeine, thebaine, narcotine, and papaverine, can be separated in approximately 20 min.